,from不是可以省略吗?A、D哪个对?

,from不是可以省略吗?A、D哪个对? prevent from from 可以省略吗 keep from中的from可以省略吗 It is necessary that we ___a foreign language.A.must master B.ought to master C.master D.should master到底选哪个啊?虚拟语气中的should不是可以省略吗?那答案C和D有什么区别? keep sb.from doing sth.和stop sb.from doing sth.中哪个from可以省略 stop sb from doing sth 中from可以省略吗 prevent sb from doing的from可以省略吗 This is the way ____he solved the difficult prolem.A which B by which C from which D /解析可以填that或in which ,我不懂为什么可以填that,不是只有在作宾语的情况下才可以省略that吗,that作宾语的话不缺少介词吗? He told me____he came back,he would call me.A.that B.when that C.that when D.when引导宾语从句that不是可以省略吗? keep away from中的away可以省略吗 1.we must do something to ______the roof falling in.A.prevent B.protect C.defend D.keep 解释说keep .from doing sth.的from不能省略.换言之prevent .from doing sth.的from可以省略了,那stop .from doing sth.和protect .from sth.的from可 To make a child love book from the very beginning is of great help.中的of可以省略吗? defend sb/sth against/from sb/sth 这里的from 和against可以省略吗? 结构式可以省略碳碳单键吗?不是简式! 时间状语从句中when可以省略吗?比如说...from the time (when) I was ten years old.这句话把when省略了这句话是对的吗? 句子She is going to a birthday party. 不是be going to do sth吗,可以省略do吗? 关于函数的极限（定理）x趋于x0左极限时f(x)=A,那么f(x0 “减或是加” 以前学的时候不是没有对0的加减吗,可以省略掉吗? 句子 may i be excused?我给的句子意思是我可以离开吗的意思,有词组be excused from,我想说 句子中是不是省略了from,如果不是,该怎么理解这个用法